Open Thermodynamic Systems Research Articles

The principle of ‘maximum energy dissipation’: a novel thermodynamic perspective on rapid water flow in connected soil structures

Preferential flow in biological soil structures is of key importance for infiltration and soil water flow at a range of scales. In the present study, we treat soil water flow as a dissipative process in an open non-equilibrium thermodynamic system, to better understand this key process. We define the chemical potential and Helmholtz free energy based on soil physical quantities, parametrize a physically based hydrological model based on field data and simulate the evolution of Helmholtz free energy in a cohesive soil with different populations of worm burrows for a range of rainfall scenarios. The simulations suggest that flow in connected worm burrows allows a more efficient redistribution of water within the soil, which implies a more efficient dissipation of free energy/higher production of entropy. There is additional evidence that the spatial pattern of worm burrow density at the hillslope scale is a major control of energy dissipation. The pattern typically found in the study is more efficient in dissipating energy/producing entropy than other patterns. This is because upslope run-off accumulates and infiltrates via the worm burrows into the dry soil in the lower part of the hillslope, which results in an overall more efficient dissipation of free energy.

Thermodynamic anomalies in open quantum systems: Strong coupling effects in the isotropic XY model

The exactly solvable model of a one dimensional isotropic XY spin chain is employed to study the thermodynamics of open systems. For this purpose the chain is subdivided into two parts, one part is considered as the system while the rest as the environment or bath. The equilibrium properties of the system display several anomalous aspects such as negative entropies, negative specific heat, negative susceptibilities in dependence of temperature and coupling strength between system and bath. The statistical mechanics of this system is studied in terms of a reduced density matrix. At zero temperature and for certain parameter values we observe a change of the ground state, a situation akin to a quantum phase transition.

Dr Olivier Coussy, Scientist and Engineer of the Mechanics and Physics of Porous Materials (1953–2010)

Dr Olivier Coussy, Scientist and Engineer of the Mechanics and Physics of Porous Materials (1953–2010)

Quasi-One-Dimensional Model of Hydrogen-Fueled Scramjet Combustors

A computationally efficient, quasi-one-dimensional, supersonic combustion ramjet (scramjet) propulsion model has been produced for use in hypersonic system design studies. The model solves a series of ordinary differential equations using a fourth-order Runge–Kutta method to describe the gas dynamics within the scramjet duct. Additional models for skin friction and wall heat transfer are also included. The equations are derived assuming an open thermodynamic system with equilibrium or simplified-chemistry combustion models. The combustion is also assumed to be mixing-limited rather than kinetically limited. This assumption allows simplification of the modeling and is justified when the model is compared against experimental results. Three test cases are used to validate the performance of the scramjet propulsion model: 1) a reflected-shock-tunnel hydrogen-fueled scramjet experiment, 2) a continuous-flow hydrogen-fueled scramjet ground test, and 3) a segment of the HyShot II flight test. The results show that the model simulates scramjet propulsion with a reasonable degree of accuracy.

Some Properties of Conservative Port Contact Systems

The dynamics of open irreversible thermodynamic systems, that is systems including both the balance equation of the energy and the entropy, has been formulated as contact vector fields with generating functions depending on some external (control) variable and called conservative port contact systems. In this paper we relate the dynamical properties of these systems (equilibrium points, asymptotic stability) to properties of the generating functions (the contact Hamiltonian functions). We show that the equilibrium points of the system satisfy certain conditions involving the contact Hamiltonian function. We also consider Lyapunov's first theorem to emphasize a stability criterion for the equilibrium points in terms of this contact Hamiltonian function and relate it to some thermodynamical properties. These results are then related to the physical phenomena that are taking place in the system.

Eshbach's handbook of engineering fundamentals

Eshbach's handbook of engineering fundamentals

Corrections to chance fluctuations: quantum mind in biological evolution?

According to neo-Darwinian theory, biological evolution is produced by natural selection of random hereditary variations. This assumption stems from the idea of a mechanical and deterministic world based on the laws of classic physics. However, the increased knowledge of relationships between metabolism, epigenetic systems, and editing of nucleic acids suggests the existence of self-organized processes of adaptive evolution in response to environmental stresses. Living organisms are open thermodynamic systems which use entropic decay of external source of electromagnetic energy to increase their internal dynamic order and to generate new genetic and epigenetic information with a high degree of coherency and teleonomic creativity. Sensing, information processing, and decision making of biological systems might be mainly quantum phenomena. Amplification of microscopic quantum events using the long-range correlation of fractal structures, at the borderline between deterministic order and unpredictable chaos, may be used to direct a reproducible transition of the biological systems towards a defined macroscopic state. The discoveries of many natural genetic engineering systems, the ability to choose the most effective solutions, and the emergence of complex forms of consciousness at different levels confirm the importance of mind-action directed processes in biological evolution, as suggested by Alfred Russel Wallace. Although the main Darwinian principles will remain a crucial component of our understanding of evolution, a radical rethinking of the conceptual structure of the neo-Darwinian theory is needed.

Energetic–exergetic-economic analyses of a cogeneration thermic power plant in Turkey

In present study the exergy and economical analysis of a cogeneration plant system in Turkey ( Esenyurt Thermic Power Plant) was performed based on the measured data during the operation time of the system. First and second laws of thermodynamics are adapted to the measured data. Furthermore, fuel-utilization efficiency, rate of power heat and rate of process heat are determined. The system is considered as a steady-state open thermodynamic system. As a result, it is found that the second law efficiency is 89.5% which is accepted as an agreeable value in archival journals. The pay back period of the plant is found 3.5 years, which is favorable time period for well designed plants in terms of the economical analysis.

¿Una ética biofísica cuantitativa para enfrentar el desafío global?

Philosophical and political discussions often become ends in circles, in which barely scratches occur without creating new structures of thought that would reveal the reality and the ways to solve the serious problems we live. Generally, each person involved in the discussion, consider that it is right in his argument and no mediator to interact in the discussion to help move the points of view, nor an arbitrator may render a verdict. And often the rhetorical skill and the weight of tradition influence the outcome of the discussions, for better or for worse. Is it possible philosophical and political debate based on science universal? In this case, the arguments would have to present diagrams to explain the systems that defend and to quantify energy flows involved, quantitatively simulate the consequences of the alternatives and generate indicators to assess the implications of the proposals. The progress of modern science enables this evolution. This new type of discussion requires training in Biophysics Economics. The science involved would be: General Systems Theory, Systemic Ecology, Thermodynamics of Open Systems and Holistic Psychology. These sciences enable a systemic approach to reality, explaining the complexity and dynamics. We could have a qualitative leap in human work and interaction with nature, whether judges, politicians and ordinary people could make decisions based on the systemic approach. Have you thought of a Systemic Ethic and the implications of this approach to religion? Or to set the price of resources and products? Or to set the value of a coin? Or to measure the sustainability of the production models? Therefore, education on these sciences is a great need and that training should occur in parallel with formal education and everyday activities of people.

Performance analysis of a 2-stroke micro free-piston swing engine

The micro free-piston swing engine (MFPSE) is a new structure, free-piston internal combustion engine. The dynamic model integrated MFPSE with a power generator and thermodynamic models in compression, power and scavenge processes based on the open thermodynamic systems were presented. A simulation was executed at given geometric parameters and initial conditions. The results manifest that the working principle of MFPSE is feasible.

Threshold behaviour in hydrological systems as (human) geo-ecosystems: manifestations, controls, implications

Abstract. In this paper we review threshold behaviour in environmental systems, which are often associated with the onset of floods, contamination and erosion events, and other degenerative processes. Key objectives of this review are to a) suggest indicators for detecting threshold behavior, b) discuss their implications for predictability, c) distinguish different forms of threshold behavior and their underlying controls, and d) hypothesise on possible reasons for why threshold behaviour might occur. Threshold behaviour involves a fast qualitative change of either a single process or the response of a system. For elementary phenomena this switch occurs when boundary conditions (e.g., energy inputs) or system states as expressed by dimensionless quantities (e.g. the Reynolds number) exceed threshold values. Mixing, water movement or depletion of thermodynamic gradients becomes much more efficient as a result. Intermittency is a very good indicator for detecting event scale threshold behavior in hydrological systems. Predictability of intermittent processes/system responses is inherently low for combinations of systems states and/or boundary conditions that push the system close to a threshold. Post hoc identification of "cause-effect relations" to explain when the system became critical is inherently difficult because of our limited ability to perform observations under controlled identical experimental conditions. In this review, we distinguish three forms of threshold behavior. The first one is threshold behavior at the process level that is controlled by the interplay of local soil characteristics and states, vegetation and the rainfall forcing. Overland flow formation, particle detachment and preferential flow are examples of this. The second form of threshold behaviour is the response of systems of intermediate complexity – e.g., catchment runoff response and sediment yield – governed by the redistribution of water and sediments in space and time. These are controlled by the topological architecture of the catchments that interacts with system states and the boundary conditions. Crossing the response thresholds means to establish connectedness of surface or subsurface flow paths to the catchment outlet. Subsurface stormflow in humid areas, overland flow and erosion in semi-arid and arid areas are examples, and explain that crossing local process thresholds is necessary but not sufficient to trigger a system response threshold. The third form of threshold behaviour involves changes in the "architecture" of human geo-ecosystems, which experience various disturbances. As a result substantial change in hydrological functioning of a system is induced, when the disturbances exceed the resilience of the geo-ecosystem. We present examples from savannah ecosystems, humid agricultural systems, mining activities affecting rainfall runoff in forested areas, badlands formation in Spain, and the restoration of the Upper Rhine river basin as examples of this phenomenon. This functional threshold behaviour is most difficult to predict, since it requires extrapolations far away from our usual experience and the accounting of bidirectional feedbacks. However, it does not require the development of more complicated model, but on the contrary, only models with the right level of simplification, which we illustrate with an instructive example. Following Prigogine, who studied structure formation in open thermodynamic systems, we hypothesise that topological structures which control response thresholds in the landscape might be seen as dissipative structures, and the onset of threshold processes/response as a switch to more efficient ways of depleting strong gradients that develop in the case of extreme boundary conditions.

Maximum Power Efficiency and Criticality in Random Boolean Networks

Random Boolean networks are models of disordered causal systems that can occur in cells and the biosphere. These are open thermodynamic systems exhibiting a flow of energy that is dissipated at a finite rate. Life does work to acquire more energy, then uses the available energy it has gained to perform more work. It is plausible that natural selection has optimized many biological systems for power efficiency: useful power generated per unit fuel. In this Letter, we begin to investigate these questions for random Boolean networks using Landauer's erasure principle, which defines a minimum entropy cost for bit erasure. We show that critical Boolean networks maximize available power efficiency, which requires that the system have a finite displacement from equilibrium. Our initial results may extend to more realistic models for cells and ecosystems.

Mathematical modelling of a steam boiler room to research thermal efficiency

This paper introduces a mathematical model of a boiler room to research its thermal efficiency. The model is regarded as an open thermodynamic system exchanging mass, energy, and heat with the atmosphere. On those grounds, the energy and energy balance were calculated. Here I show several possibilities concerning how this model may be applied. Test results of the coefficient of thermal efficiency were compared to a real object, i.e. a steam boiler room of the Provincial Hospital in Wloclawek (Poland). The tests were carried out for 18 months. The results obtained in the boiler room were used for verification of the mathematical model.

On the formation of crystalline microstructures of monolayers seen in terms of qualitative diffusion-type models at mesoscale

It is well known (see, e.g., K. A. Beklemishev and D. B. Berg, Pis’ma Zh. Tekh. Fiz. 33 (19), 40 (2007) [Tech. Phys. Lett. 33, 825 (2007)]) that many diffusion-type growth models allow qualitative features of growing microstructures to be obtained without employing any special information on the molecules constituting the microstructural domains. It has also been noted that the time needed to obtain a polycrystalline structure must be carefully estimated by engaging statistical-mechanical ensemble-averaging methods. The latter seems to be, in general, a difficult task because the problem is left as non-ergodic. The former, in turn, is supposed to be remedied while realizing that the qualitative estimates can become quantitative when offered at the mesoscopic level and when appropriately supported by a suitable construction of the diffusion function. In addition to comprising the Gibbs (non-negative) entropy production framework as a firm basis deeply rooted in the first law of thermodynamics for open thermodynamic systems, this construction can be seen as good as the frequently used Avrami-Kolmogorov phenomenology. This type of proposal cannot be easily postponed in the modeling of phospholipid monolayers or other two-dimensional amphiphilic, soft-matter-type systems.

Inevitable evolution: back toThe Originand beyond the 20th Century paradigm of contingent evolution by historical natural selection

Since neo-Darwinism arose from the work of Darwin and Mendel evolution by natural selection has been seen as contingent and historical being defined by an a posteriori selection process with no a priori laws that explain why evolution on Earth has taken the direction of the major evolutionary trends and transitions instead of any other direction. Recently, however, major life-history trends and transitions have been explained as inevitable because of a deterministic selection that unfolds from the energetic state of the organism and the density-dependent competitive interactions that arise from self-replication in limited environments. I describe differences and similarities between the historical and deterministic selection processes, illustrate concepts using life-history models on large body masses and limited reproductive rates, review life-history evolution with a wider focus on major evolutionary transitions, and propose that biotic evolution is driven by a universal natural selection where the long-term evolution of fitness-related traits is determined mainly by deterministic selection, while contingency is important predominately for neutral traits. Given suitable environmental conditions, it is shown that selection by energetic state and density-dependent competitive interactions unfolds to higher level selection for life-history transitions from simple asexually reproducing self-replicators to large bodied organisms with senescence and sexual reproduction between males and females, and in some cases, to the fully evolved eusocial colony with thousands of offspring workers. This defines an evolutionary arrow of time for open thermodynamic systems with a constant inflow of energy, predicting similar routes for long-term evolution on similar planets.

Last Word on Viewpoint: Emergent phenomena and the secrets of life

VIEWPOINTLast Word on Viewpoint: Emergent phenomena and the secrets of lifePeter T. MacklemPeter T. MacklemPublished Online:01 Jun 2008https://doi.org/10.1152/japplphysiol.90453.2008MoreSectionsPDF (27 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmailWeChat to the editor: What a wealth of stimulating viewpoints these letters (2, 3) provide! The approaches they describe to gain a deep understanding of life include: understanding of how complex systems self-organize to best absorb the energy gradients to which they are exposed; quantum field theory; a neat idea that a potential physical law governing the asymmetry between order and disorder is waiting to be discovered; use of non-linear dynamics to make the abstract chaotic nature of life concrete and definite; understanding of how optimization of entropy production is achieved; even Oriental transcendentalism. Different ways of analyzing a complex phenomenon is surely the best approach to gain comprehensive knowledge. But we must heed Similowski's (2) warning: unless we all talk the same language and are familiar with each others tools and concepts we will generate confusion and heat rather than light and understanding.Yates (2) states that there are many secrets of life, and implies that “The Secret” sits unknown at the core. But I claim, based on present knowledge, that understanding heritable characteristics, how order is achieved in open thermodynamic systems and how Darwinian evolution has designed extant, as opposed to extinct life, is the core of what life is. If we understand these three secrets and apply our research to solving the three great and universal problems listed by Fredberg (2), new theories of disease and how to treat them should be a crowning achievement of the new “emergency” medicine.Understanding life is the responsibility of the biologist, and the physician. It is their raison d'etre. Yet because life obeys the laws of physics, the involvement of physicists is welcome and necessary. But immediately problems of concepts and communication arise, leading to the discomfort described by Fredberg. To the biologist and physician it is self-evident that the future is governed by uncertainty and that time, often of the essence in treating the sick, is irreversible. Both irreversible time and uncertainty are incorporated in the Second Law, which is the reason we welcome it and perhaps why physicists do not. But my (almost nonexistent) understanding of quantum mechanics is that its uncertainties require statistical mechanics to quantify probabilities. If so, even if quantum field theory explains life, we must cope with uncertainty, and the certainties of great theories of physics do not help. For us God does play dice with the world, at least for the time being.REFERENCES1 Macklem PT. Viewpoint: Emergent phenomena and the secrets of life. J Appl Physiol; doi: 10.1152/japplphysiol.00942.2007.Link | ISI | Google Scholar2 Robbins PA, Suki B, Fredberg JJ, Yates FE, Bates JHT, Similowski T, Straus C, Fiamma M-N, Glass L, Seely AJE. Commentaries on Viewpoint: Emergent phenomena and the secrets of life. J Appl Physiol; doi: 10.1152/japplphysiol.zdg-7945-vpcomm.2008.Link | ISI | Google Scholar3 Stephens NL. Commentary on Viewpoint: Emergent phenomena and the secrets of life. J Appl Physiol; doi: 10.1152/japplphysiol.90387.2008.Link | ISI | Google ScholarAUTHOR NOTESAddress for reprint requests and other correspondence: P. T. Macklem, PO Box 250, Landsdowne, Ontario, Canada K0E 1L0 (e-mail: [email protected]) Download PDF Previous Back to Top Next FiguresReferencesRelatedInformation More from this issue > Volume 104Issue 6June 2008Pages 1851-1851 Copyright & PermissionsCopyright © 2008 the American Physiological Societyhttps://doi.org/10.1152/japplphysiol.90453.2008History Published online 1 June 2008 Published in print 1 June 2008 Metrics

Homeokinetics/Homeodynamics: A Physical Heuristic for Life and Complexity

This essay addresses the puzzlement, the missing piece, sensed when attempts are made to build a bridge from the synchronic, informational genotype to the diachronic, dynamic phenotype—a regular mapping that seems to be extraphysical. There is no formal, dynamic foundation for the bridge. Albert Einstein, Max Delbrück, and Erwin Schrödinger all expressed acute awareness of limitations of contemporary physics when considering biology because physics addresses much simpler sysems. As a proposed remedy, a new physical heuristic, homeokinetics, developed by Arthur Iberall and Harry Soodak (and later recast for biology by me as homeodynamics) is introduced here as a foundation for comprehending energy flows and transformations in complex systems, including those in metabolic networks of living systems. Their individual dynamic stability is flexible and marginal—it must allow for adaptations and changes in physiological and behavioral states to occur in an orderly fashion as external circumstances change. At the population level, stability must allow for evolvability of chemical networks that have energized terrestrial living systems for about 3.9 billion years. Homeokinetics/homeodynamics emphasizes that persistent, marginally stable metabolic networks, as open thermodynamic systems, necessarily organize energy processing as cyclic, physical action modes. Conceptually, that organization is under 2 kinds of biological time pressure—time as a cycle that daily closes the thermodynamic books and time as an arrow orthogonally pressing the cyles into the future, creating joint time as a helix. In most animals, after maturity, the helix is additionally shaped into a tapered ellipsoid by a senesence process that gains influence as dynamic degrees of freedom are frozen out by the constructions of development.

JM interim management statement, 3Q 2007-08

We propose that chemical evolution can take place by natural selection if a geophysical process is capable of heterotrophic formation of liposomes that grow at some base rate, divide by external agitation, and are subject to stochastic chemical avalanches, in the absence of nucleotides or any monomers capable of modular heredity. We model this process using a simple hill-climbing algorithm, and an artificial chemistry that is unique in exhibiting conservation of mass and energy in an open thermodynamic system. Selection at the liposome level results in the stabilization of rarely occurring molecular autocatalysts that either catalyse or are consumed in reactions that confer liposome level fitness; typically they contribute in parallel to an increasingly conserved intermediary metabolism. Loss of competing autocatalysts can sometimes be adaptive. Steady-state energy flux by the individual increases due to the energetic demands of growth, but also of memory, i.e. maintaining variations in the chemical network. Self-organizing principles such as those proposed by Kauffman, Fontana, and Morowitz have been hypothesized as an ordering principle in chemical evolution, rather than chemical evolution by natural selection. We reject those notions as either logically flawed or at best insufficient in the absence of natural selection. Finally, a finite population model without elitism shows the practical evolutionary constraints for achieving chemical evolution by natural selection in the lab.

REMOVED: The driving force behind genomic diversity

Eukaryote genomes contain excessively introns, intergenic and other non-genic sequences that appear to have no vital functional role or phenotype manifestation. Their existence, a long-standing puzzle, is viewed from the principle of increasing entropy. According to thermodynamics of open systems, genomes evolve toward diversity by various mechanisms that increase, decrease and distribute genomic material in response to thermodynamic driving forces. Evolution results in an excessive genome, a high-entropy ecosystem of its own, where copious non-coding segments associate with low-level functions and conserved sequences code coordinated activities. The rate of entropy increase, equivalent to the rate of free energy decrease, is identified with the universal fitness criterion of natural selection that governs populations of genomic entities as well as other species.

Money as Social Exergy

It has been proposed that open thermodynamic systems will act to dissipate available energy gradients by self-organizing into coherent structures that, with time, evolve and develop into nested hierarchies – panarchies – that adapt to internal and external changes according to a characteristic adaptive cycle. This paper seeks to apply these ideas in the purely societal realm by investigating the role of money in economic systems. Money represents the value embodied in goods; a value that is separate from the exact nature of those goods. We suggest that money thereby liberates the ‘free value’ of economic desire and that this free value has properties analogous to energy. The result is the self-organization of structures and systems (‘econosystems’) that dissipate this ‘free value’. Econosystems act at different scales, and nested levels of econosystems form a panarchy, having effects that can be observed. In particular, it appears that money facilitates the creation of relationships between econosystem actors, increasing the connectedness of the econosystems that envelop those actors. We have identified a phenomenon whereby freed social value (i.e. money) can aggregate, or pool, at a larger econosystem scale in structures such as banks. These pools act as gradients that actors at the neighborhood scale can exploit for self-organization in the econosystem. Thus, econosystem actors appear to be freed from thermodynamic constraints by using money as a means of self-organization. However, because of these pools of aggregated social exergy, connectedness is increased at the larger scale of the econosystem. The potential consequence of this dynamic is that money may act to push larger scale econosystems toward a state of heightened vulnerability to collapse, while freeing smaller scale actors from apparent constraints. In this way, we propose that money acts to skew information feedback loops between econosystem actors and larger scale structures such as economies and ecosystems.